The present invention relates to improved means for guiding the weft-carrying grippers and their control straps through the shed of gripper looms.
In the technique of weaving machines, there are known to be various systems for guiding through the shed the weft-carrying grippers and the straps controlling the same. A first system provides for a single plurality of guide elements, aligned parallel to the reed, which guide merely the straps, only on one side thereof facing the reed, with the considerable advantage of stressing the warp yarns to a very limited extent, but with the drawback of having to adopt different precautions--not always acceptable--like the use of rigid straps for controlling the grippers, and a careful choice in the distribution of the masses in the grippers in order to guarantee an efficient and reliable weft yarn exchange between the two grippers. With this system, it is moreover necessary to use a precision-machined reed, mounted very precisely, as the reed cooperates with said elements in guiding the straps and the grippers, this involving structural complications and cost increases.
A second system provides for two pluralities of guide elements, aligned on two rows parallel to the reed and guiding the straps on both sides, but with the drawback of heavily stressing the yarns being woven. In fact: the guide elements next to the reed determine greater deviations of the warp yarns which facilitate stresses and breaking; the weft yarns may get caught in said elements and consequently break; the warp yarns may get caught in the strap and in the guide elements (especially when they are loose, as in the case of weaving highly beaten articles) with consequent stresses and breaking.
In any case, in all the known systems, the guide elements house into a single seat thereof, and engage with the same surfaces, either only the straps--as in the aforementioned examples--or, if desired, the straps and projections of the grippers positioned like extensions of said straps.